Seafoam causing underhood smoke

[RegularGuy55]

I am about to change plugs on my '93 Camry V6, (car has 228,000 miles on it, with roughly 50,000 on the existing spark plugs) so I decided to clean out the engine first with Seafoam. I got the engine warm, set the idle at roughly 1000 RPM, then used a spray bottle to squirt the Seafoam cleaner into the power brake booster vacuum hose.

I started seeing smoke coming from the backside of the engine, from the rear bank of cylinders. I expected tailpipe smoke, but not smoke from the engine.

I'm thinking it could be a bad head gasket or warped head, but I'd like to hear if anyone else has any ideas.

Thanks!

[Eye8Pussies]

it's doubtful that it's either

take a closer look and you'll probably see that it's coming out of an exhaust gasket, be it the exhaust manifold to block, exhaust manifold to y-pipe, or from the o2 bung or egr gaskets

take a closer look (from the side of the engine bay or from under the car) and it should be pretty easy to figure out

[dave255]

^Agreed. I know someone who had this happen. It turns out the flex pipe was eroded pretty badly, so some exhaust gases were able to leak out and work their way up between the engine and firewall. It was alarming at first, but a simple fix.

[RegularGuy55]

I'll check again, this time looking in the areas suggested. I kind of doubt this is from the flex pipe, since I had a new exhaust system (including a flex pipe) installed less than a year ago. Still, I guess a weld could have cracked, so I won't rule anything out. I do think I'm going to need another pair of hands to make this diagnosis easier.

[pmesfun]

possible oil burning onto the exhaust manifold from a rear valve cover gasket leak?

[RegularGuy55]

Originally Posted by pmesfun

possible oil burning onto the exhaust manifold from a rear valve cover gasket leak?

If it was an oil leak from the valve cover, I think it would smoke whenever I ran the engine. This smoke starts after a dose of Seafoam cleaner, but after the cleaner is out of the engine, the smoke goes away. Also, the engine doesn't use oil. I go 3,000 miles between changes and I never have to add oil between changes.

[pmesfun]

Ok, then its probably an exhaust leak. Check the egr tube gaskets, like Eye8 said.

[Chris Crash]

I bet you spilled some on the engine.

[RegularGuy55]

Yeah, that's my next step. Not today, though. I started getting some cross-eyed looks from the family for spending Easter Sunday in the garage.

[RegularGuy55]

Originally Posted by Chris Crash

I bet you spilled some on the engine.

When I use Seafoam with my old 4bbl Buick, I usually do manage to spill, but for this exercise I put the Seafoam into a spray bottle, then butted the spray nozzle up to the end of the vacuum hose. The spray bottle keeps you from pouring too fast and ending up with a hydrolock. Even if there was some over spray, the bottle was nowhere near where the smoke was coming from.

[EEngineer]

it's usually the exhaust manifold gaskets that leak since they are usually untouched.
they are metal gaskets and they change shape due to the heat and ususally leaks a tiny bit, but it won't do any major harm.

[71Corolla]

Seafoam is a very thin pure petroleum even at room temperature. Heat it up, and it becomes extremely thin and will leech its way through any tiny gap or imperfection. So it is no surprise that it will find its way through older exhaust gaskets, that does not necessarily mean there is a problem.

After using Seafoam through the intake a couple of times, I concluded the stuff has the potential to do more harm than good.

[RegularGuy55]

Originally Posted by 71Corolla

Seafoam is a very thin pure petroleum even at room temperature. Heat it up, and it becomes extremely thin and will leech its way through any tiny gap or imperfection. So it is no surprise that it will find its way through older exhaust gaskets, that does not necessarily mean there is a problem.

After using Seafoam through the intake a couple of times, I concluded the stuff has the potential to do more harm than good.

I read somewhere that guys used to pour uncooked short grain rice into a running engine to clean out the carbon. I cringe at the idea of putting anything solid into an engine, even if it will be cooked or pulverized away. I rely on the chemical cleaners instead.

I also realize that we don't see the level of internal engine carbon they did a few decades ago. Fuel delivery systems are so much more sophisticated that they don't allow overly rich mixtures unless they malfunction. I can't say the same is true for varnish and other fuel-related deposits.

I've had good results using Seafoam over the years. I use it diluted in the gas tank, and I'll put some in the crankcase oil just before an oil change. It also helped an old V8 pass my state emissions tests.

[EEngineer]

^that's the weirdest thing i've heard
imagine all those people who wouldave loved to eat that rice
*yum!*

[kasperjames]

wow. love the rice story. any leads on who told you? idlike to look into this. sounds good enough to write about.